阅读说明：本技术 单纵模与非单纵模双波长激光交替调q输出方法及激光器 (Single-longitudinal-mode and non-single-longitudinal-mode dual-wavelength laser alternate Q-switching output method and laser ) 是由 金光勇 董渊 金龙 陈薪羽 于永吉 于 2019-05-09 设计创作，主要内容包括：本发明公开了一种单纵模与非单纵模双波长激光交替调Q输出方法及激光器,该激光器包括：第一泵浦源、第一激光增益介质、起偏器、第二泵浦源、第二激光增益介质、第一激光全反射镜、第二激光全反射镜、四分之一波片、电光调Q晶体和激光输出镜,当电光调Q晶体迅速加压时,输出第二波长非单纵模激光,当电光调Q晶体阶跃式退压时,输出第一波长单纵模激光。本发明方案可以获得较宽波长范围的双波长激光、较大的波长间差值,在输出脉冲序列上呈现出单纵模与非单纵模双波长脉冲交替状态,并且激光增益介质的种类不受限定。(The invention discloses a single longitudinal mode and non-single longitudinal mode dual-wavelength laser alternative Q-switching output method and a laser, wherein the laser comprises the following components: the laser comprises a first pumping source, a first laser gain medium, a polarizer, a second pumping source, a second laser gain medium, a first laser holophote, a second laser holophote, a quarter-wave plate, an electro-optic Q-switched crystal and a laser output mirror. The scheme of the invention can obtain the dual-wavelength laser with a wider wavelength range and a larger difference value between the wavelengths, and the single longitudinal mode and non-single longitudinal mode dual-wavelength pulse alternating state is presented on the output pulse sequence, and the type of the laser gain medium is not limited.)

1. A single longitudinal mode and non-single longitudinal mode dual wavelength laser alternatively Q-switched output laser, comprising: the laser device comprises a first pumping source, a first laser gain medium, a polarizer, a second pumping source, a second laser gain medium, a first laser holophote, a second laser holophote, a quarter-wave plate, an electro-optic Q-switched crystal and a laser output mirror, wherein:

the first pump source is arranged in front of the first laser gain medium and used for providing pulse pump light for the first laser gain medium;

the second pump source is arranged in front of the second laser gain medium and used for providing pulse pump light for the second laser gain medium;

the first laser holophote, the first laser gain medium, the polarizer, the electro-optic Q-switched crystal and the laser output mirror form a first wavelength lambda₁A laser resonant cavity;

the second laser holophote, the second laser gain medium, the quarter wave plate, the first laser holophote, the first laser gain medium, the polarizer, the electro-optic Q-switched crystal and the laser output mirror form a second wavelength lambda₂A laser resonant cavity;

when the electro-optical Q-switched crystal is stepped to back the voltage, the lambda is output₁Wavelength single longitudinal mode laser, when the electro-optic Q-switched crystal is rapidly pressurized, the output lambda₂The wavelength non-single longitudinal mode laser periodically performs rapid pressurization and step decompression on the electro-optically Q-switched crystal, and the laser alternately outputs dual-wavelength non-single longitudinal mode laser and single longitudinal mode laser。

2. The laser of claim 1, wherein the first laser gain medium is positioned coaxially with the second laser gain medium and aligned with the laser output direction.

3. The laser of claim 1, wherein said second laser total reflection mirror is disposed on one side of the second laser gain medium and said quarter wave plate is disposed on the other side of the second laser gain medium.

4. The laser of claim 1, wherein said first laser holophote is disposed between the quarter wave plate and the first laser gain medium, and said polarizer is disposed between the first laser gain medium and the electro-optically Q-switched crystal.

5. The laser of claim 1, wherein the electro-optic Q-switch crystal and the laser output mirror are sequentially disposed on a side of the polarizer remote from the first laser gain medium.

6. The laser of claim 1, further comprising a first laser power supply and a second laser power supply, wherein:

the first laser power supply is connected with the first pumping source and used for providing power for the first pumping source;

and the second laser power supply is connected with the second pumping source and is used for providing power for the second pumping source.

7. The laser of claim 6, further comprising a Q-switching module connected to the electro-optically Q-switching crystal, the first laser power supply, and the second laser power supply for applying a Q-switching drive signal to the electro-optically Q-switching crystal.

8. The laser of claim 7, wherein the Q-switched drive signal is a stepped high voltage signal.

9. The laser of claim 7, further comprising a first temperature control system, a second temperature control system, and a central control system, wherein:

the first temperature control system and the second temperature control system are respectively arranged behind the first laser gain medium and the second laser gain medium, are connected with the central control system and are used for controlling the working temperature of the laser according to the instruction of the central control system;

the central control system is connected with the first laser power supply, the second laser power supply, the first temperature control system, the second temperature control system and the Q-switching module and is used for uniformly controlling the first laser power supply, the second laser power supply and the Q-switching module.

10. A single longitudinal mode and non-single longitudinal mode dual wavelength laser Q-switched output method, applied to the laser device as claimed in any one of claims 1-9, wherein the method comprises:

applying a quarter first wavelength voltage to the electro-optically Q-switched crystal;

the first pump source performs pulse pumping on the first laser gain medium, the first wavelength laser resonant cavity is in a high-loss state, the first laser gain medium is in a population inversion state, when the inversion population of the first laser gain medium reaches the maximum, the electro-optic Q-switched crystal is in step-back pressure, the voltage applied to the electro-optic Q-switched crystal becomes zero, and the first wavelength single longitudinal mode laser is output;

the second pumping source performs pulse pumping on the second laser gain medium, the voltage applied to the electro-optic Q-switched crystal is zero, the second wavelength laser resonant cavity is in a high-loss state, the second laser gain medium is in a population inversion state, when the inversion population of the second laser gain medium reaches the maximum, a quarter of second wavelength voltage value is rapidly applied to the electro-optic Q-switched crystal, and second wavelength non-single longitudinal mode laser is output;

the rapid pressurizing and step-type decompressing states of the electro-optic Q-switching crystal are periodically repeated, and the dual-wavelength single-longitudinal-mode laser and the non-single-longitudinal-mode laser which are alternately output by Q switching are obtained.

Technical Field

The invention relates to the field of solid lasers, in particular to a single longitudinal mode and non-single longitudinal mode dual-wavelength laser alternate Q-switching output method and a laser.

Background

The dual-wavelength pulse laser has been widely applied in the aspects of laser ranging, environment monitoring, laser remote sensing and laser radar. Compared with the single longitudinal mode pulse laser, the non-single longitudinal mode pulse laser has wider line width, but can often obtain larger pulse energy output, and the non-single longitudinal mode pulse dual-wavelength laser can realize ultra-long distance detection in the technical field. The single longitudinal mode pulse laser has a narrow line width, is a detection light source for ultrahigh-precision and ultrahigh-sensitivity detection, and the narrower the line width of the laser, the higher the measurement precision. However, since extra elements are required to be inserted into the laser resonant cavity for obtaining the laser resonant cavity, the output capacity of the laser resonant cavity is often lower than that of a non-single longitudinal mode pulse laser. Therefore, when the dual-wavelength pulse laser is a non-single longitudinal mode pulse laser and a single longitudinal mode pulse laser, respectively, coarse detection of an ultra-long distance and high-precision detection of a short distance can be realized in the technical fields of laser ranging, environment monitoring, laser remote sensing, laser radar and the like. The existing common Q-switched dual-wavelength laser mainly adopts a single laser gain medium to obtain the simultaneous output of dual-wavelength laser. However, when two kinds of wavelength laser are generated in the same gain medium, there is strong gain competition between transition spectral lines, which affects the stability of laser output; in addition, the precise design of the transmittance of the output mirror is used for ensuring that the lasers with two wavelengths have the same threshold value, which brings great challenges to the film system of the output mirror; moreover, most of the output dual-wavelength laser is non-single longitudinal mode laser, and non-single longitudinal mode and single longitudinal mode pulse laser output cannot be realized.

At present, the disclosed dual-wavelength laser mainly outputs dual-wavelength laser simultaneously, wherein one known technique related to the present invention is disclosed by Zhang Qiang et al (Zhang Qiang, Yao bolt, Wenwukin, etc.. high-power laser diode pumping Nd: YAG continuous dual-wavelength laser [ J ]. Chinese laser 2006, 33 (5): 577-. In the figure, 101 is a 1064nm laser resonator total reflection mirror, 102 is a 1319nm laser resonator total reflection mirror, 103 is an Nd: YAG laser crystal, 104 is LD Bar, 105 is 1319nm laser resonator output mirror, 106 is 1064nm laser resonator output mirror. However, the known technology has the following disadvantages: firstly, lasers with two wavelengths of 1064nm and 1319nm are generated by the same laser crystal, and have a strong gain competition relationship with each other, so that the running stability of the laser is influenced; secondly, the two wavelength lasers are operated continuously at the same time, and the alternate output cannot be realized; thirdly, the two kinds of wavelength laser are both output in a non-single longitudinal mode, and the structural scheme can not realize the alternate output of the dual-wavelength pulse laser with one kind of wavelength laser in a single longitudinal mode and the other kind of wavelength laser in a non-single longitudinal mode; fourthly, the wavelength difference between the two-wavelength lasers is limited by the type of the laser crystal.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a single longitudinal mode and non-single longitudinal mode dual-wavelength laser alternating Q-switching output method and a laser.

According to an aspect of the present invention, a single longitudinal mode and non-single longitudinal mode dual wavelength laser alternatively Q-switched output laser is provided, the laser comprising: the laser device comprises a first pumping source, a first laser gain medium, a polarizer, a second pumping source, a second laser gain medium, a first laser holophote, a second laser holophote, a quarter-wave plate, an electro-optic Q-switched crystal and a laser output mirror, wherein:

the first pump source is arranged in front of the first laser gain medium and used for providing pulse pump light for the first laser gain medium;

the second pump source is arranged in front of the second laser gain medium and used for providing pulse pump light for the second laser gain medium;

the first laser holophote, the first laser gain medium, the polarizer, the electro-optic Q-switched crystal and the laser output mirror form a first wavelength lambda₁A laser resonant cavity;

the second laser holophote, the second laser gain medium, the quarter wave plate, the first laser holophote, the first laser gain medium, the polarizer, the electro-optic Q-switched crystal and the laser output mirror form a second wavelength lambda₂A laser resonant cavity;

when the electro-optical Q-switched crystal is stepped to back the voltage, the lambda is output₁Wavelength single longitudinal mode laser, when the electro-optic Q-switched crystal is rapidly pressurized, the output lambda₂The wave length of non-single longitudinal mode laser is used to periodically and rapidly pressurize the electro-optical Q-switched crystalAnd step-type decompression, wherein the laser alternately outputs dual-wavelength non-single longitudinal mode laser and single longitudinal mode laser.

Optionally, the first laser gain medium and the second laser gain medium are coaxially disposed and aligned with a laser output direction.

Optionally, the second laser total reflection mirror is disposed on one side of the second laser gain medium, and the quarter-wave plate is disposed on the other side of the second laser gain medium;

optionally, the first laser total reflection mirror is disposed between the quarter-wave plate and the first laser gain medium, and the polarizer is disposed between the first laser gain medium and the electro-optical Q-switched crystal.

Optionally, the electro-optic Q-switched crystal and the laser output mirror are sequentially disposed on a side of the polarizer away from the first laser gain medium.

Optionally, the laser further comprises a first laser power supply and a second laser power supply, wherein:

the first laser power supply is connected with the first pumping source and used for providing power for the first pumping source;

and the second laser power supply is connected with the second pumping source and is used for providing power for the second pumping source.

Optionally, the laser further includes a Q-switching module, and the Q-switching module is connected to the electro-optical Q-switching crystal, the first laser power supply, and the second laser power supply, and is configured to apply a Q-switching driving signal to the electro-optical Q-switching crystal.

Optionally, the Q-switched driving signal is a step-type high-voltage signal.

Optionally, the laser further comprises a first temperature control system, a second temperature control system and a central control system, wherein:

the first temperature control system and the second temperature control system are respectively arranged behind the first laser gain medium and the second laser gain medium, are connected with the central control system and are used for controlling the working temperature of the laser according to the instruction of the central control system;

the central control system is connected with the first laser power supply, the second laser power supply, the first temperature control system, the second temperature control system and the Q-switching module and is used for uniformly controlling the first laser power supply, the second laser power supply and the Q-switching module.

According to another aspect of the present invention, a single longitudinal mode and non-single longitudinal mode dual wavelength laser alternate Q-switched output method is provided, which is applied to the laser as described above, and the method includes:

applying a quarter first wavelength voltage to the electro-optically Q-switched crystal;

the first pump source performs pulse pumping on the first laser gain medium, the first wavelength laser resonant cavity is in a high-loss state, the first laser gain medium is in a population inversion state, when the inversion population of the first laser gain medium reaches the maximum, the electro-optic Q-switched crystal is in step-back pressure, the voltage applied to the electro-optic Q-switched crystal becomes zero, and the first wavelength single longitudinal mode laser is output;

the second pumping source performs pulse pumping on the second laser gain medium, the voltage applied to the electro-optic Q-switched crystal is zero, the second wavelength laser resonant cavity is in a high-loss state, the second laser gain medium is in a population inversion state, when the inversion population of the second laser gain medium reaches the maximum, a quarter of second wavelength voltage value is rapidly applied to the electro-optic Q-switched crystal, and second wavelength non-single longitudinal mode laser is output;

the rapid pressurizing and step-type decompressing states of the electro-optic Q-switching crystal are periodically repeated, and the dual-wavelength single-longitudinal-mode laser and the non-single-longitudinal-mode laser which are alternately output by Q switching are obtained.

The invention provides a method and a laser capable of obtaining single longitudinal mode and non-single longitudinal mode dual-wavelength laser alternate Q-switched output. The laser adopts double pumping sources to alternately pump double laser gain media, and the two laser gain media work in turn, so that the heat effect of the laser can be greatly reduced under the condition of high pumping power. In addition, under the condition that a Q-switched pulse signal is applied to the electro-optical Q-switched crystal once, two pulse laser outputs of a single longitudinal mode and a non-single longitudinal mode can be realized, and an effective way is provided for alternate output of high-repetition-frequency single longitudinal mode and non-single longitudinal mode lasers.

Drawings

FIG. 1 is a schematic diagram of a prior art dual wavelength laser configuration;

FIG. 2 is a schematic diagram of a single longitudinal mode and non-single longitudinal mode dual wavelength laser alternative Q-switched output laser according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the timing of driving signals and the timing of forming a laser according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a pulse sequence for a single longitudinal mode and non-single longitudinal mode dual wavelength laser alternatively Q-switched output laser in accordance with an embodiment of the present invention;

fig. 5 is a flowchart of a single longitudinal mode and non-single longitudinal mode dual-wavelength laser alternate Q-switching output method according to an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings.

Fig. 2 is a schematic structural diagram of a single longitudinal mode and non-single longitudinal mode dual-wavelength laser alternatively Q-switched output laser according to an embodiment of the present invention, and as shown in fig. 2, the single longitudinal mode and non-single longitudinal mode dual-wavelength laser alternatively Q-switched output laser includes: the laser gain control device comprises a first pumping source 15, a first laser gain medium 5, a polarizer 3, a second pumping source 11, a second laser gain medium 10, a first laser total reflector 6, a second laser total reflector 9, a quarter wave plate 7, an electro-optic Q-switching crystal 2 and a laser output mirror 1, wherein:

the first pump source 15 is disposed in front of the first laser gain medium 5, and is configured to provide pulsed pump light for the first laser gain medium 5;

the second pump source 11 is disposed in front of the second laser gain medium 10 and configured to provide pulsed pump light for the second laser gain medium 10;

the first laser holophote6. The first laser gain medium 5, the polarizer 3, the electro-optical Q-switched crystal 2 and the laser output mirror 1 form a first wavelength lambda₁A laser resonant cavity;

the second laser holophote 9, the second laser gain medium 10, the quarter wave plate 7, the first laser holophote 6, the first laser gain medium 5, the polarizer 3, the electro-optic Q-switched crystal 2 and the laser output mirror 1 form a second wavelength lambda₂A laser resonator is provided.

In this embodiment, the two resonators in which the electro-optic Q-switching crystal 2 is located share one laser output mirror 1, and the purpose is to realize coaxial laser output, when the electro-optic Q-switching crystal 2 is stepped to be depressed, the output λ is outputted₁Wavelength single longitudinal mode laser, when the electro-optic Q-switched crystal 2 is rapidly pressurized, the output lambda₂The wavelength is not single longitudinal mode laser. Wherein, the square wave voltage is applied during the rapid pressurization, and the rising time and the falling time are both less than 10 nanoseconds.

In one embodiment of the present invention, the first pump source 15 and the second pump source 11 are both semiconductor pump sources.

In one embodiment of the present invention, the laser further comprises a first laser power supply 14 and a second laser power supply 12, wherein:

the first laser power supply 14 is connected to the first pump source 15 and configured to provide power to the first pump source 15;

the second laser power supply 12 is connected to the second pump source 11, and is configured to provide power to the second pump source 11.

The first laser power supply 14 and the second laser power supply 12 may be independently arranged power supplies or may be the same integral power supply.

Namely, the pump sources of the first laser gain medium 5 and the second laser gain medium 10 are a first pump source 15 and a second pump source 11, respectively, and the two pump sources are respectively powered by a first laser power supply 14 and a second laser power supply 12.

In one embodiment of the present invention, the first laser gain medium 5 and the second laser gain medium 10 are coaxially disposed and aligned with the laser output direction.

In one embodiment of the present invention, the second laser total reflection mirror 9 is disposed on one side of the second laser gain medium 10, and the quarter-wave plate 7 is disposed on the other side of the second laser gain medium 10;

in one embodiment of the invention, the first laser total reflection mirror 6 is arranged between the quarter-wave plate 7 and the first laser gain medium 5, and the polarizer 3 is arranged between the first laser gain medium 5 and the electro-optical Q-switched crystal 2.

In one embodiment of the present invention, the electro-optical Q-switched crystal 2 and the laser output mirror 1 are sequentially disposed on a side of the polarizer 3 away from the first laser gain medium 5.

In an embodiment of the present invention, the crystal used in the electro-optical Q-switched crystal 2 is LN, KD × P, KDP, LiNbO₃Isoelectric optical crystal.

In an embodiment of the present invention, the laser further includes a Q-switching module 16, and the Q-switching module 16 is connected to the electro-optical Q-switching crystal 2, the first laser power supply 14, and the second laser power supply 12, and is configured to apply a Q-switching driving signal to the electro-optical Q-switching crystal 2.

In an embodiment of the present invention, the laser further comprises a first temperature control system 4, a second temperature control system 8 and a central control system 13, wherein:

the first temperature control system 4 and the second temperature control system 8 are respectively placed behind the first laser gain medium 5 and the second laser gain medium 10, are connected with the central control system 13, and are used for controlling the working temperature of the laser according to the instruction of the central control system 13;

the central control system 13 is connected to the first laser power supply 14, the second laser power supply 12, the first temperature control system 4, the second temperature control system 8, and the Q-switching module 16, and is configured to perform unified control on the first laser power supply 14, the second laser power supply 12, and the Q-switching module 16, for example, control triggering and delaying of the first laser power supply 14, the second laser power supply 12, and the Q-switching module 16, and control the first temperature control system 4 and the second temperature control system 8 to switch the operating temperature of the laser.

The Q-switched driving signal is a step-type high-voltage signal, and the falling edge of the Q-switched driving signal is in a two-step form, as shown in fig. 3, the rising edge of the Q-switched driving signal adopts a rapid rising mode, and the falling edge of the Q-switched driving signal adopts a step-type signal form, so that the main purpose is to obtain a narrow pulse width non-single longitudinal mode pulse laser output with relatively high pulse energy at the rising edge stage of the Q-switched driving signal, and obtain a single longitudinal mode pulse laser output of laser with another wavelength at the falling stage of the Q-switched driving signal by using a pre-lasing technique. The working process of the pre-laser technology can be divided into the following three stages in terms of time sequence:

a. seed light formation stage

Unlike the general Q-switched technique, the signal generator used in the pre-lasing technique is a two-step signal generator that generates a periodic stepped voltage signal that varies with time. In a high voltage state, the Q-switching loss in the cavity is high, and the inside of the laser is subjected to reversed particle accumulation; during the process of regulating high voltage to low voltage, the Q loss in the cavity is changed from high to low. At this time, the partially inverted particle transitions from a high energy level to a low energy level and generates a photon to form seed light.

b. Mode competition phase

When a low voltage is applied to the Q-switched crystal, the intra-cavity losses are low. And the low voltage duration is prolonged, the seed light carries out a natural mode selection process due to the existence of gain and loss difference values among different modes. Meanwhile, because the single-pass gain of the central mode is slightly larger than that of the adjacent mode, and the single-pass loss of the central mode is slightly smaller than that of the adjacent mode, the adjacent mode gradually disappears along with the increase of the duration along with the continuation of the mode competition process, and finally the single longitudinal mode seed light only with the central mode is formed.

c. Output process

When the Q-switch is fully turned on, a large number of the inverted particles are transited from the high energy level to the low energy level, and a giant pulse laser is formed. The intensity level of the single longitudinal mode seed light is far larger than that of noise, so that the seed light can replace the noise as initial oscillation starting noise of the laser, and the seed light can amplify the seed light and inhibit other modes again to form the single longitudinal mode pulse laser.

The invention provides a single longitudinal mode and non-single longitudinal mode dual-wavelength laser alternative Q-switched output laser which effectively combines decompressionBased on the principle of electro-optical Q-switching of the formula and the pressurization type. That is, when the electro-optic Q-switched crystal 2 is stepped to reduce the voltage, the first wavelength lambda can be realized₁A single longitudinal mode laser Q-switched output, and when the electro-optic Q-switched crystal 2 is rapidly pressurized, the second wavelength λ can be realized₂The non-single longitudinal mode laser Q-switched output can realize the alternate output of the single longitudinal mode and the non-single longitudinal mode dual-wavelength laser Q-switched pulse by periodically carrying out rapid pressurization and step-type pressure relief on the electro-optical Q-switched crystal 2.

Specifically, the specific working principle of the single-longitudinal-mode and non-single-longitudinal-mode dual-wavelength laser alternate Q-switched output laser is as follows: when applying a quarter lambda to the electro-optic Q-switching crystal 2₁During the wavelength voltage, the first pump source 15 of the first laser gain medium 5 performs a pulsed pumping of the first laser gain medium 5 due to λ₁Wavelength laser is changed into linearly polarized light through the polarizer 3, under the action of an external electric field, the linearly polarized light passes through the electro-optic Q-switching crystal 2 twice in a reciprocating manner, the polarization direction of the original linearly polarized light is deflected by 90 degrees, the polarization direction of the polarizer 3 is orthogonal to the transmission direction of the polarizer and is reflected out of the resonant cavity, and oscillation cannot be formed in the resonant cavity, so that the first wavelength resonant cavity is in a high-loss state, and the first laser gain medium 5 is in a population inversion (energy storage) state; at this time, the second pump source 11 of the second laser gain medium 10 is in an intermittent state. When the population of the first laser gain medium 5 reaches a maximum inversion, the voltage applied to the electro-optically Q-switched crystal 2 is reduced by a fraction in the phase A of FIG. 3, i.e., when the electro-optically Q-switched crystal 2 is stepped back, in which phase λ is formed₁Seed light of wavelength laser is subjected to sufficient mode competition to form lambda₁Wavelength single longitudinal mode seed laser. At λ₁After the wavelength single longitudinal mode seed laser is formed, the voltage drop applied to the electro-optically Q-switched crystal 2 is zero, lambda₁The wavelength single longitudinal mode seed laser is amplified to finally form lambda₁And outputting the wavelength single longitudinal mode laser.

At the next moment, the second pump source 11 pumps the second laser gain medium 10 in pulses, the first pump source 15 of the first laser gain medium 5 is in an intermittent state, and the voltage applied to the electro-optically Q-switched crystal 2 isAnd (4) zero. At the laser wavelength λ₂Under the action of the quarter-wave plate 7 in the resonant cavity, the polarization direction of the polarized light passing through the electro-optical Q-switched crystal 2 back and forth rotates by 90 degrees, so that the polarizer 3 is orthogonal to the transmission direction thereof, the resonant cavity of the second laser gain medium 10 is in a high-loss state, and the second laser gain medium 10 is in a population inversion (energy storage) state. When the number of reversed particles of the second laser gain medium 10 reaches the maximum, the stored energy reaches the peak value, and a quarter lambda is rapidly applied to the electro-optic Q-switching crystal 2₂The wavelength voltage value is in the B-phase of FIG. 3, where λ₂The wavelength laser has the lowest intra-cavity loss, and the intra-cavity laser is rapidly gain-amplified to obtain the giant pulse laser output with narrow pulse width, i.e. form lambda₂And (3) outputting the wavelength non-single longitudinal mode laser Q-switched.

By doing so, a single longitudinal mode and non-single longitudinal mode dual-wavelength laser alternating Q-switched output sequence as shown in FIG. 4 can be obtained, where s in FIG. 4 represents a single longitudinal mode pulse laser, and m represents a non-single longitudinal mode pulse laser.

In an embodiment of the present invention, the first laser gain medium 5 is Nd: YAG crystal with size of 4X 50mm³The two ends are plated with 1319nm antireflection films (T is more than 99%); the second laser gain medium 10 is Nd: YVO₄Crystals of phi 4X 50mm in size³And the two ends are plated with anti-reflection films with the thickness of 1064nm (T is more than 99%). The first laser total reflector 6 is a plano-concave mirror, the concave surface of the first laser total reflector is plated with a 1319nm high-reflectivity film (R is more than 99%), the second laser total reflector 9 is a plano-plano mirror, the surface close to the cavity is plated with a 1064nm high-reflectivity film (R is more than 99%), the laser output mirror 1 is a plano-plano mirror, and the surface close to the cavity is plated with a 1319nm high-reflectivity film&A 1064nm partial transmittance film having a transmittance of 4% for a laser beam having a wavelength of 1319nm, a transmittance of 6% for a laser beam having a wavelength of 1064nm, and a coating of 1319nm on the outside&Anti-reflection film of 1064nm laser. Polarizer 3 plated 1319nm&And the 1064nm laser Brewster angle antireflection film has the transmissivity higher than 98% for the two-wavelength laser. The corresponding wavelength of the quarter-wave plate 7 is 1064nm, and the two light-transmitting surfaces are plated with 1064nm antireflection films (T is more than 98%). The first pump source 15 and the second pump source 11 are both strip-shaped arrays composed of 808nm laser diodes. The first temperature control system 4 and the second temperature control system 8 are controllableThe laser system works at room temperature of 25 ℃, and the central control system 13 mainly controls the triggering and time delay of the first laser power supply 14, the second laser power supply 12 and the Q-switching module 16. The timing of the signals applied to the first laser power supply 14, the second laser power supply 12, and the Q-switch module 16 is shown in fig. 3. Wherein, V₁Waveform V for exciting the first pump source 15₂Waveform V for exciting second pump source 11_QIs a voltage waveform applied to the electro-optically Q-switched crystal 2. For the laser configuration shown in fig. 2, the relief will result in a wavelength λ₁The Q-switched single longitudinal mode laser outputs generate a wavelength lambda when pressurized₂The Q-switched non-single longitudinal mode laser output. From the whole time sequence, the pulse sequence of the single longitudinal mode and the non-single longitudinal mode dual-wavelength laser output alternately is generated as shown in fig. 4.

According to another aspect of the present invention, there is also provided a single longitudinal mode and non-single longitudinal mode dual wavelength laser Q-switched output method, as shown in fig. 5, the method includes steps S501-S504:

in step S501, a quarter-wavelength first-wavelength voltage is applied to the electro-optically Q-switched crystal 2;

in step S502, the first pump source 15 performs pulse pumping on the first laser gain medium 5, the first wavelength laser resonant cavity is in a high loss state, the first laser gain medium 5 is in a population inversion state, when the inversion population of the first laser gain medium 5 reaches a maximum, the electro-optic Q-switched crystal 2 is in step-back, the voltage applied to the electro-optic Q-switched crystal 2 becomes zero, and the first wavelength single longitudinal mode laser is output;

in step S503, the second pump source 11 performs pulse pumping on the second laser gain medium 10, the voltage applied to the electro-optically tuned Q crystal 2 is zero, the second wavelength laser resonant cavity is in a high loss state, the second laser gain medium 10 is in a population inversion state, and when the population inversion of the second laser gain medium 10 reaches a maximum, a quarter of the second wavelength voltage value is rapidly applied to the electro-optically tuned Q crystal 2 to output a second wavelength non-single longitudinal mode laser;

in step S504, the electro-optic Q-switched crystal 2 is periodically repeated to rapidly pressurize and step-back the pressure state, so as to obtain the dual-wavelength single-longitudinal-mode and non-single-longitudinal-mode laser with alternately-switched Q output.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.